Production of motor fuel



May 15, 1945.

-V J. P. JoNEs PRODUCTION OF MOTOR FUEL Filed oct. 5, 19412 v Planas May15, 194s PRODUCTION F MOTOR FUEL Jean 'P. Jones, Bartlesville, Okla.,assignor to Phillips Petroleum Com Delaware pany, a corporation ofApplication October 5, 1942, SerlalNo. 460,851

4 Claims.

This invention relates to the production of normally liquid hydrocarbonsof high octane Inumber lfrom a sulfur-containing hydrocarbon material ofa, lower octane number. particularly to the production of a relativelysulfur-free saturated hydrocarbon fraction boiling in the motor fuelrange from a sufur-containing normally liquid hydrocarbon fraction.

Many speciilcations for premium motor fuels, particularly those for usein air-cooled aviation engines, require that the motor fuel besubstantially saturated in character and that it have not only a highoctane number but also that this octane number be securedl with theaddition of only small amounts of anti-detonants, such as the commonlyused tetraethyl lead.- Motor fuels of this nature are generally preparedby blends of synthetically produced isoparaflin hydrocarbon fractions.together with fractions of naturally occurring hydrocarbons having moreor less narrow boiling ranges. Most oi' the synthetic hydrocarbonfractions are inherently sulfur-free; either because sulfur is readilyremoved from the charge stock to the synthesis steps or because thesynthesis processes tend to remove It relates whole, are subjectd toisomerization to form isoparaillns having higher octane numbers. In oneparticular modification of this invention the hydrocarbon'eiliuent fromthe alkylation step is passed to a separating means, fractions of lowoctane number are separated therefrom and subjected to isomerization,thehydrocarbon eiiluents sulfur-containing-compounds from thehydrocarbon materials treated... However, such synthesis processes aregenerally carried out in the presence of a catalyst which is adverselyaffected by sulfur-containing compounds which may be present in thecharge stock. Furthermore, considerable difficulty often results fromsulfur-containing compounds which are present in the fractions ofhydrocarbons obtained from natural sources such as natural gasoline andstraightrun gasoline. to remove such sulfur-containing compounds fromthese lfractions are included processes Among the means which areusedmeans is recovered a hydrocarbon material of hig'h octanevnumber,containing isoparalns resulting both from the alkylation and from theisomerization steps, which is essentially saturated in character andwhichis also essentialiysulfurfree.

An object of this invention is to produce hydrocarbons of high octanenumber boiling in the motor fuel range.

A lfurther object of this invention-is to convert a vsuliur-cor'itaininghydrocarbon fraction into a saturated sulfur-free hydrocarbon fractionboiling in the motor fuel range. Further, objects and advantages of myinvention will become apparent to one skilled in the art from theaccompanying disclosure and discussion.

Reference will now be made to the drawing which. forms a part of thisspecification which shows diagrammatically an arrangement of ap; paratuswhich may be used in practicing my in\L vention, the said. discussionserving also to exA emplify the invention.

wherein such compounds are decomposed and the f sul-fur removed ashydrogen sulfide. Although in most instances such processes are simpleand inexpensive as well as being highlyemcient, they Y such converted tohydrogen ysulfide and olenns, andv the hydrogen sulfide is removed andthe fraction through line I 0 and passed through valve Il to a suitable,heater I2, and then through line I3 to a desulfurizer I 4.

If desired, such a charge stock may be separated by an initialfractionation into one or more fractions which containl the major partof the sulfur compounds present in the initial charge so that thematerial treated in desulfurizer il will not have such a large volume.Such a fractionav tion may be effected by passing the charge from lineIII throughl line ii controlled by valve I6' is passed toen alkylationstep'wherein'the olens u to separating means l1. undesirable low boiling.may be separated and 2 asraooo d material may be discharged throughvalved line y I8 and undesirable high boiling materials may i bedischarged through valved line I 9. One or more fractions which are lowin sulfur content discharged, as through valved lines and 2|. One ormore fractions which are high in sulfur content may be sepa.

.rated as through valved lines 2 2 and 23 and passed to line I0 on thefar side of valve Ii for treatment in desulfurizer Il. In heater l2 thesulfur-containing hydrocarbon material is heatedto a suitabledesulfurizing temperature, which will be generally between about 500 and'150 or '800 F., and is passed through line I3 into contact with asuitable desulfurization catalyst in 'desulfurizer Il.' 'Such a catalystmay be bauxite,

bauxite treated with sodium hydroxide 'or barium hydroxide, brucite,caliche or other suitable contactl materials. `The pressure ispreferably between about 0-100 pounds gage and the contact time ispreferably between about 0.1 and 2.0 seconds. Under these conditionsmost lof the sulfur-containing compounds, especially the mercaptans, areconverted to hydrogen sulfideA that dehydrogenation should not takeplacefto 1 an extent greater than that of about 8 or 10 l per cent. u i

From desulfurizer llthe effluents pass through l line 24 to'sulfurremoval means 25. This may be 4a simple fractional distillation columnwhereby hydrogen sulde, and any fr ee hydrogen, are removed byfractional distillatio and may be dis charged through valved'line 2B.Such fractional distillation may, i-f desired, be supplemented orreplaced byw unsaturated hydrocarbons, is passed from unit 25 throughline 21 to alkylator 30. In some instances the material may of itselfcontain sumcient low boiling isoparafbn to react satisfactorily with theunsaturated hydrocarbons` present under the alkylation conditionsexisting in alkylator 30.

However, it will generally be desired to add a lowboiling isoparafnn.particularly isobutanel from with a suitable alkali such as sodiumhydroxide or sodium carbonate.' A 45 substantially sulfur-freematerial,which contains vulue und if it is not eumeienuy 1w 1u to alkylator llthe desired effect may be secured d by adding the olenn containingcharge to a circulating reaction mixture, or by adding it at a pluralityof pointsg'to areacting stream, as will v g be appreciated byone skilledin the art. It is )desired that the products of such alkylation ree4actions will boil'in the motor fuel Arange, and

Y the isoparamn introduced and which` is reacted should be chosen withregard to olenic material present in the hydrocarbon fraction passingthrough line 21 with-this in mind. Eiuents'of separating means I! and afraction of high octane 'u number, which is saturated and sulfur free,can y be recovered through line 4l controlled aby' valve As a desiredmodification of my invention it is preferred to separate the hydrocarbonmaterial o which is charged to separating means' 35 into one or morefractions of low octane number and into `one or more fractions of highoctane number and to subject the frarstiomor fractions, oi'Y low octanenumber tov4 an isomerization reaction whereby saturated fractions ofhigh octane number are 2 obtained. when this `mudnieuuuu is iue1uded,

fractions of lowjoctane number are recovered as u .by means of one or@more yalved lines l2, and M, and fractions of high octane number arerecovered by one-or more of the valved lines l0,

3 4r and 4s.' undesired nignbouing material may be discharged fromvalved line I1. e Low-boiling isoparafilnic material 'may be removedthrough line '36 and recycled entirely or in part through alve I'I ordischarged through valve 48.

I Aparafilnic hydrocarbon material of low octane number comprising oneor more of the fractions` oflow octane number separated from separatingmeans I6, and substantially free from sulfurcontaining compounds whichare inJurious tc line 50 to isomerizer BI, wherein it is subjected tc anisomerization catalyst under l)reaction conditions of time, temperatureand pressure such ai' to eillectv a substantial conversion of normal ormore highly branched parain hydrocarbons catalysts suitable for theisomerization reaction include hydrogen fluoride, or one or more of the.metal halides commonly identied as Friedel-- Crafts catalysts,especially aluminum chloridez aluminum bromide, ferrie chloride and thelike.

' with such metal mildes it is preferable@ operate 'l in the presence ofsmall amounts of corresponiiing hydrogen halide. vThe hydrocarbonmaterial the aikylation reaction passthrough line 34 to l manyisomerization catalysts, is passed through u l only slightly branchedperailln hydrocarbons intr .may comprise or'consist of isobutaneproduced in Y vdescribed and passed from f' through line li and valve31.

other sources, through line 2B. This low-boiling isoparaflln may beintroduced from a suitable outside source through line 3i and .valve I2,or

being treated may be present in either liquid or vapor phase with any ofthese catalysts. satisfactory operation having been secured with bothconditionslta'ghe metalhalide may be used alone` @epartmg mem u w or "ona s lesupport such as activated char- The mmion yeeuu, dried emes oralumina sel, dehydrated bauxite or the like, or it may be dissolved in asubsequenty step of the process as wili'be later out in the alkylator orallrylationzone n'ieiude nydrcnucric acid, sulfuric dcid, uiuminumchloride, phosphoric acid, sodium chloro-alumi- ...1s-preferablyconducted m of a thehydrocarbon material when such is being suitablealkylation catalyst since the product is l generally more saturated thanthat resulting from 55 a noncatalytic alkylation carried outl atelevated .terl'iperatures andpressures. Suitable -.catalysts treatedvinthe liquid phase. Suitable conditions for the use of aluminum -chlorideinclude a Atemperature in the range of about 1'75 to 250 F., l to 5% lofhydrogen chloride, with a reaction time between about 5 minutes andanhour. ,With hydrotluoric acid askthe isomeriz'ation. :ata.lyst.

mtemdthe mm Temperatures, pressures, and the reaction is preferablycarried'out t'BOO to .350 F. and a similar reactiontime'. Withthereaction times will depend-to a certain extentl upon the .catalystused-and can be readily ascertlyst mnticnedrit `is generally prefegapleso 4 fonanylparticular instance by onesicllled l limit the yreactiontime that between about 30 in the art.' It is'desirabIe that :the olefinconand 50% of the paramos centration inthe-'alkylationsonebekept atslow." tion reaction. From isomsriser'll the eilluents are passed to theseparator I through and can be recycled at least in part through` valvesu back to the isomerizer" sl. Generally it is desirable to discharge apart of this material from the system as through valvev 55. Ahydrocarbon material is removed' from separating means 53 through ^line51, and. is mixed with an alkaline solution which is Passed by pump 58through line 59, to neutralize any residual HCl and other acidicmaterials which may be present. 'I'he mixture is passed to separator 80and the alkaline solution settles and may be Iwithdrawn through line Bl, A part or-all of this solution may be withdrawn through valve B2, butpreferablyk a part is recycled through valve 6I to pump 58.Freshlalkaline solution maybe introduced through valve 84. A hydrocarbonfraction containing isoparaiiins of high octane number is recoveredthrough line l5 and may be recovered as a product of the process throughvalve 65. However,`it is often desirable to subject this material tofurther fractionation to separate frai tions of high octane number asproducts and also to separate fractions of low octane number which canbe recycled to isomerizer 5I./ I iind it desirable to eiect such aseparation by passingthe i. A process for producinga-saturated motorfuel having an improved octane number and an'. improved response totheaddition-.of antidetonants, which comprises subjecting a sulfur-con- 1taining normally liquid paraninic'hydrocarbon material boiling in themotor fuel range to desul'- furization at an elevated temperature in thepresence ot a desulfurization catalyst to convert "sulfur-containingcompounds to hydrogen sul d and olens, removing hydrogen-sulfide fromeilluents oi' said treatment, passing a resultantv desulfurizedlhydrogen sulilde-free normally liquid hydrocarbon material to anallcyiation zone, passing also to'said alkylation zone a low-boilingisoparamn in an amount sumcient to eii'ect a reaction with theunsaturated hydrocarbons in said desulfurized hydrocarbon material,eiecting an alkylation reaction between said unsaturated hy saidfraction of low octane number to isomerization to convert paramnhydrocarbons contained therein into paramn hydrocarbons of more highlybranched structure including isobutane, recovering from eflluents ofsaid isomerizaton a paraf- J inic fractionboiling in the motor fuelrange and hydrocarbon eilluents of the isomerization from line 65through valve B1 to line 34 and to separating means 35, so' thateilluents of the alkylation and eilluents of the isomerizaton arefractionated 40 together. 'I'his has the added advantage of giving aunified cyclic process for the production of a single product of highoctane number 'which can :be recovered through line 40. When isobutaneis produced in isomerizer 5| it will constitute or be contained in thematerial passed from separating means 35 through valve 31 and line 28 toalkylator 30 rand in some instances will supply all of the low boilingisoparafn which is used in akylator 30. In such a case it will beunnecessary to add other isoparaiiins and other isoparamnic material tothe process through valve 32 except perhaps when a continuous run isfirst being put into operation. It willbe appreciated, of course, thatwhen more than one fraction of low octane number is available forisomerization from separating means 35, each fraction may be subjectedto isomerization separately in apparatus not shown, but similar to thatshown and discussed, Iso that each fraction is reacted under conditionswhich are optimum for that particular fraction. However, in manyinstances the additional expense is not warranted and the single Aisomerization step shown will be found entirely satisfactory.

Many modincations and variations of this invention may obviously be usedand can be adapted by one skilled in the art without departing from thespirit of the disclosure. Itwill be understood that the flow diagram isschematic, that only essential pieces of equipment and conditions have`been described, and the'function and modiiica- Serve 8.8

combining said `fraction with the aforesaid fraction of higher octanenumber to form a composite product of the` process, recovering also fromeffluents ofsaid isomerization isobutane and passing said isobutane tosaid alkylation zone as at least a part of said low-boiling isoparaiiln.

2. A process for producinga saturated-motor' fuel having an improvedoctane numberand an improved response `:to the addition ofantidetonants, which comprises subjecting a sulfurcontaining normallyliquid paraflinic hydrocar-` bon material boiling in the motor fuelrange to desulfurization at an elevated temperature in the presence of adesulfurization catalyst to convert sulfur-containing compounds tohydrogen sul fide and olens, removing hydrogen suliide from eilluents ofsaid treatment, passing a resultant desulfurized-hydrogen sulde-i'reenormally lio-1 uid hydrocarbon material to an alkylaton zone,

passing also to said alkylation zone a low-boiiing isoparailln in anamount suiilcient to effect a reaction with the unsaturated hydrocarbonsin said desulfurized hydrocarbon material, eiecting an alkylationreaction between said unsaturated hydrocarbons and said low boilingisoparailins to form higher .boiling paraiilns, passing hydrocarbonsefliuent from said alkylation to a separating means, separating fromsaid hydrocarbons a normally liquid paraiilnic hydrocarbon fraction of ylow-octane number, subjecting said fraction of low octane number toisomerization to convert paraiiin hydrocarbons contained therein into c5parai'lln hydrocarbons of more highly branched structure, passinghydrocarbons eiliuent from said isomerization to the aforesaidseparating means, and recovering from said separatingmeans a paralnlchydrocarbon fraction lboiling in the motor fuel range of high octanenumber and containing paraiiin hydrocarbons resulting from saidalkylation and also paraffin hydrocarbons resulting from saidisomex'lzation.

3.v A process for producing a saturated motor fuel having an improvedoctane number and an improved response to the addition of antidetonants,which comprises subjecting asulfurcontaining normally liquid paramnichydrocarbon material boiling inthe motor fuel range to bon materialboiling in the motor fuel range to desulfurization at an elevatedtemperature in the presence 'of a desulfurizatipn catalyst to convertsulfur-containing compounds to hydrogen sul- 'de and oleflns, removinghydrogen sulfide from eiiiuentsof said treatment, passing a resultantdesulfurized hydrogen sulde-free normally liquid hydrocarbon material toan alkylation zone,

passing also to said alkylation zone a low-boiling isoparaiiin in anamount sufficient to eilect a reaction with 'the unsaturatedhydrocarbons in said desulfurized hydrocarbon material, eiiectingA analkylation reaction between said unsaturated hydrocarbons and said lowboiling isoparamn to form higher boiling parains, passing hydrocarbonseiiluent from said alkylation'to a separating means, separating fromsaid hydrocarbons a nordesulfurization at an elevated temperature in thepresence of a desulfurization catalyst to `convert"sulfurcontainingcompounds to hydrogen I i ah alkymuon catalyst to produce a parammchydrocarbon product,l passing hydrocarbons eiiluent Y from s aidalkylation to a fractional distillation,

mally liquid parafnic hydrocarbon fraction of low-octane number,subjecting said fraction of low octane number to isomerization toconvert paramn hydrocarbons contained therein into parain hydrocarbonsof more highly branched structure including ispbutane, passinghydrocarbons effluent from said isomerization to the aforesaidseparating means, separating from said means an isobutane fractioncontaining isobutane produced in said isomerization and passning saidisobutane fraction to said alkylation zone as at least a part of saidlow-boiling isopar-ailin, and recovering from said vseparating meansfamotor fuelrang'e of high octane number `and containing parafiinhydrocarbons-resulting from said alkylation and also paraiiin`hydrocarbons resulting from said isomerizatiom 4. A process forproducing a saturated motor fuel having an improved octane number andanremoving from said fractional distillation a plu-4 r'ality of normallyliquid parainc hydrocarbon fractions of low octane number and in themotor y .fuel range, subjecting said fractions f low octane -v number toisonierization to convert parafiin hy drocarbons contained therein intolow-boiling isoparamme hydrocarbon fraction honing in the parafllnichydrocarbons including isobutane. passing `hydrocarbons emuent from'said isomerization to the aforesaid fractional distillation, recoveringan isobutane fraction from said fra'ctional distillation, and passingsame to said alkyiation as aforesaid, and recovering also from y saidfractional distillation a plurality ofv substantiallyvsuifur-freenormally liquid paramnic hydrocarbon fractions of high octane numberboiling in the motor fuel range and containing -paraiiin hydrocarbonsresulting from said alkylation and also vparafn hydrocarbons resulting,ofi-om said isomerization as well as paramn hydrocari' bons originallycontained inthe first said sulimproved response to the ,addition ofanti-v detonants, which comprises subjecting a sulfur. Q containingnormally liquid paramnic hydrocar- It. is hereby certified that. arruappeairs Bieprinted specification c iisrrfnrcam or" comisarios;

MP, roms.;

fur-containing hydrocarbon material, and combining said -fractions toform aparainic motor fuel product of high 'octane number.

` JONES.

' of tho'raboye mnuberd' patent,xa-aqui.ring..sorxiecti.onjas'-follrcws';v lag'evflfusoo--v ondcolumnl,line "fu,l for-,"subv-jeotd" read "subjected-fling 145, for"hereinafter" road-'.--jhoreinbeforet-l-g 'page li.,second-column.'lline'2tffclam'll.,

v fsi'gned und .equis/u: fili-u t' "say 'or August, 'L /"D,

i* (seal) Y Leslie Frazer First-Assistant .Commissioner lof Patents.

improved response to the addition of antidetonants, which comprisessubjecting asulfurcontaining normally liquid paramnic hydrocarbonmaterial boiling inthe motor fuel range to bon material boiling in themotor fuel range to desulfurization at an elevated temperature in thepresence 'of a desulfurizatipn catalyst to convert sulfur-containingcompounds to hydrogen sul- 'de and oleflns, removing hydrogen sulfidefrom eiiiuentsof said treatment, passing a resultant desulfurizedhydrogen sulde-free normally liquid hydrocarbon material to analkylation zone,

passing also to said alkylation zone a low-boiling isoparaiiin in anamount sufficient to eilect a reaction with 'the unsaturatedhydrocarbons in said desulfurized hydrocarbon material, eiiectingA analkylation reaction between said unsaturated hydrocarbons and said lowboiling isoparamn to form higher boiling parains, passing hydrocarbonseiiluent from said alkylation'to a separating means, separating fromsaid hydrocarbons a nordesulfurization at an elevated temperature in thepresence of a desulfurization catalyst to `convert"sulfurcontainingcompounds to hydrogen I i ah alkymuon catalyst to produce a parammchydrocarbon product,l passing hydrocarbons eiiluent Y from s aidalkylation to a fractional distillation,

mally liquid parafnic hydrocarbon fraction of low-octane number,subjecting said fraction of low octane number to isomerization toconvert paramn hydrocarbons contained therein into parain hydrocarbonsof more highly branched structure including ispbutane, passinghydrocarbons effluent from said isomerization to the aforesaidseparating means, separating from said means an isobutane fractioncontaining isobutane produced in said isomerization and passning saidisobutane fraction to said alkylation zone as at least a part of saidlow-boiling isopar-ailin, and recovering from said vseparating meansfamotor fuelrang'e of high octane number `and containing parafiinhydrocarbons-resulting from said alkylation and also paraiiin`hydrocarbons resulting from said isomerizatiom 4. A process forproducing a saturated motor fuel having an improved octane number andanremoving from said fractional distillation a plu-4 r'ality of normallyliquid parainc hydrocarbon fractions of low octane number and in themotor y .fuel range, subjecting said fractions f low octane -v number toisonierization to convert parafiin hy drocarbons contained therein intolow-boiling isoparamme hydrocarbon fraction honing in the parafllnichydrocarbons including isobutane. passing `hydrocarbons emuent from'said isomerization to the aforesaid fractional distillation, recoveringan isobutane fraction from said fra'ctional distillation, and passingsame to said alkyiation as aforesaid, and recovering also from y saidfractional distillation a plurality ofv substantiallyvsuifur-freenormally liquid paramnic hydrocarbon fractions of high octane numberboiling in the motor fuel range and containing -paraiiin hydrocarbonsresulting from said alkylation and also vparafn hydrocarbons resulting,ofi-om said isomerization as well as paramn hydrocari' bons originallycontained inthe first said sulimproved response to the ,addition ofanti-v detonants, which comprises subjecting a sulfur. Q containingnormally liquid paramnic hydrocar- It. is hereby certified that. arruappeairs Bieprinted specification c iisrrfnrcam or" comisarios;

MP, roms.;

fur-containing hydrocarbon material, and combining said -fractions toform aparainic motor fuel product of high 'octane number.

` JONES.

' of tho'raboye mnuberd' patent,xa-aqui.ring..sorxiecti.onjas'-follrcws';v lag'evflfusoo--v ondcolumnl,line "fu,l for-,"subv-jeotd" read "subjected-fling 145, for"hereinafter" road-'.--jhoreinbeforet-l-g 'page li.,second-column.'lline'2tffclam'll.,

v fsi'gned und .equis/u: fili-u t' "say 'or August, 'L /"D,

i* (seal) Y Leslie Frazer First-Assistant .Commissioner lof Patents.

